The present invention relates to insulating windows or storm windows for interior use and more particularly to improve extruded plastic panel molding for forming and mounting interior insulating windows.
The usefulness of storm windows is generally well known. Energy shortages and rising costs of heating and coolinghave increased the use of storm windows since they can greatly reduce heat loss. As an alternate to the expensive permanent exterior storm windows, the use of a simple additional pane attached to interior window frames has been found quite effective and economical. References specifically illustrating such uses include U.S. Pat. Nos. 4,069,641 issued to DeZutter and 3,939,620 issued to Bero. Other references illustrating similar panel mounting or framing elements include U.S. Pat. Nos. 3,455,080 issued to Meadows and 3,360,893 issued to Wattelez. The first two of these patents, DeZutter and Bero, most clearly illustrate the field of the present invention. Each involves the use of a panel frame which is adhesively to an interior window frame and which provides some means for retaining the edges of an insulating window pane. DeZutter teaches a snap-in retaining leaf for the window pane while Bero teaches a retaining portion hinged to the base which snaps into engagement with the base. The device taught by Meadows, while not being designed for adhesively mounting to a window frame, provides other features including essentially fluid-tight-sealing soft ribs on the frame and a leaf retaining arrangement for accommodating panes of different thickness. The Wettelez device is another hinged frame member and is arranged for nailing to a window frame.
While the Meadows type frame provides an essentially fluid tight seal and provides some allowance for various pane thickness, the structure is relatively complicated, both in shape and in the requirement of dual extrusion of different materials. The simpler, more practical frames as taught in particular by DeZutter, on the other hand provide a less fluid tight seal and less positive mechanical link between the pane retaining leaf and the base member.
It can be seen therefore that a simple single material extruded plastic insulating window frame having improved anchoring of a pane retaining leaf which is also useful for panes having a variety of thicknesses would be desirable.